The present invention relates to a capacitive discharge ignition device, and more particularly to such a device which is adapted to lessen rise of temperature of a generator coil (exciter coil) of an engine.
As an ignition device of an engine for automobile, there have been used in the prior art a normal ignition device 1 shown in FIG. 3 and a voltage doubler ignition device 2 shown in FIG. 4. The normal ignition device 1 shown in FIG. 3 is adapted to charge a capacitor 4 for ignition with a positive power of a generator coil 6 which causes an alternating electric power by the rotation of the engine, and to discharge by a switching element while keeping the charge. Thus, the negative power of the generator coil is adapted to short circuit at a diode 8.
Also, the voltage doubler ignition device shown in FIG. 4 provides a second capacitor 12 which is charged by the negative power of the generator coil 6. The charging is made from the second capacitor 12 to a first capacitor 4 when inverting into the positive power. The ignition device is further charged with the positive power to obtain the double voltage and after charging, is adapted to bring the generator coil 6 to a short circuit condition by a regulator (+Reg) 14 for discharge through the switching element 16 (SCR.sub.1) thereby to limit the power of the generator coil.